CUET · CHEMISTRY · PYQ PAPER 2023
Answer the question on the basis of passage given below :
Formaldehyde is the first member of the aldehydic series. It is present in green leaves of plants where its presence is supposed to be due to the reaction of \(CO_2\) with water in the presence of sunlight and chlorophyll. Commercially, formaldehyde is obtained by the controlled oxidation of methane in the presence of molybdenum oxide (\(MoO\)) acting as a catalyst. Formaldehyde is a constituent of a number of polymers also called resins. These are non volatile solids or semi solids which are obtained directly from certain plants and can be synthesized in the laboratory.
Match List I with List II
| LIST I | LIST II |
| A. Bakelite formaldehyde resin | I. Condensation polymers |
| B. Melamine formaldehyde resin | II. Phenol and formaldehyde |
| C. Urea formaldehyde resin | III. Melamine and formaldehyde |
| D. Bakelite \(\&\) Melamine formaldehyde resin | IV. Unbreakable cups and laminated sheets |
Choose the correct answer from the options given below:
- A A-I, B-II, C-III, D-IV
- B A-II, B-III, C-IV, D-I
- C A-III, B-II, C-IV, D-I
- D A-IV, B-III, C-I, D-II
Answer & Solution
Correct Answer
(B) A-II, B-III, C-IV, D-I
Step-by-step Solution
Detailed explanation
A. Bakelite formaldehyde resin is formed from Phenol and formaldehyde. \(\rightarrow\) A-II B. Melamine formaldehyde resin is formed from Melamine and formaldehyde. \(\rightarrow\) B-III D. Bakelite & Melamine formaldehyde resin are Condensation polymers. \(\rightarrow\) D-I C.…
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- Read the passage carefully and answer the questions
Optically active polyhydroxy aldehydes or ketones or molecules which provide such units on hydrolysis are called carbohydrates. They can be broadly classified as monosaccharides, disaccharides and polysaccharides depending on their behavior towards hydrolysis. They are also classified as reducing or non-reducing sugars. Another class of biomolecules is proteins which are polymers of twenty different amino acids linked by peptide bonds. Amino acids can be classified as acidic, basic or neutral depending on the relative number of amino and carboxyl groups in their molecule. The essential amino acids cannot be synthesized by our body and hence must be provided through diet. Nucleic acids are the polymers of nucleotides which in turn consist of a base, pentose sugar and phosphate. There are two types of nucleic acids namely, DNA and RNA which differ in the composition of sugar and a base.
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